There is something wrong with the random number, what can I do ??

I have succeeded in them all except : (I don't Know what is the wrong) --->> My programming code at the bottom

test3(LineTests)
expected:<[YES]> but was:<[NO]>

AND :

test6(LineTests)
expected:<[YES]> but was:<[NO]>

Code :

int sum = 0;
for (int i = 0; i < peopleInLine.length - 1 ; i++ )
sum = sum + peopleInLine[i];
if (sum == peopleInLine[peopleInLine.length - 1])
return "YES";
return "NO";